The present invention relates to an improved keyboard arrangement for a computer, word processor or other keyboard operated device.
The development of information processing technology has resulted in creation of a new occupational specialty: the rapid inputting of large amounts of data into an information processing system. Typically, this function is performed by an operator who sits at a video display terminal and inputs information by depressing keys on a keyboard. Examples of such occupational specialists include secretaries, accounting or bookkeeping personnel, and those performing other clerical functions. In some instances, such a keyboard operator may spend as many as eight to twelve hours per day inputting information on a computer type keyboard.
While similar clerical information processing functions have been performed for many years, recent developments have accentuated the repetitive nature of the task. In particular, the replacement of the manual and electric typewriter by computers and word processors has eliminated many of the previously required ancillary operations, such as periodic carriage return, putting paper into the machine, and the like. While these advances in turn have resulted in a desirable increase in productivity, that is, speed and efficiency of the information inputting function, they have at the same time eliminated almost altogether all departures from the purely repetitive motion involved in performing the inputting of information. It has been estimated, for example, that an efficient keyboard operator may strike up to 12,000 keys per hour on a sustained basis.
On result of this evolutionary specialization is the recognition of a new type of occupational injury known as "cumulative trauma disorder" ("CTD"). CTD's differ from the more traditional forms of job related illnesses in that they are not directly traceable to any single incident or accident, but rather develop over a protracted period due to sustained performance of harmful repetitive motions. A particular type of CTD which is especially prevalent among keyboard operators is carpal tunnel syndrome, a degenerative disease involving injury to the nerves which pass through the wrist from the forearm to the hand due to inflammation of the tendons which run together with them through an opening known as the carpal tunnel. If left untreated, the symptoms of carpal tunnel syndrome become progressively more severe and can prove painful and debilitating, as well as costly.
One of the environmental factors which has been the focus of much attention in recent years as a potential cause of CTD's, or carpal tunnel syndrome in particular, is the configuration of the well established design for computer keyboards. Heretofore, commercially available keyboards have almost invariably been manufactured as a planar array of keys which is typically inclined toward the operator at an elevation of several degrees. In order to operate such a keyboard, it is necessary for the operator to pronate his wrists by about 30.degree. so that the palms of his hands face substantially directly downward toward the flat surface of the keyboard, and the tips of his fingers are therefore elevated above the keys at an approximately equal distance. At the same time the wrists must be bent upwards by a few degrees in order to accommodate the incline of the keyboard. Such an unnatural positioning of the hands, wrists and forearms accompanied by long term repetitive motions of the wrists and fingers as the keys are struck can cause the sort of irritation of the tendons in the carpal tunnel which can lead to carpal tunnel syndrome.
Recently, numerous efforts have been made to develop a keyboard configuration which eliminates, or at least minimizes, the need for such awkward orientation of the hands, wrists and forearms. One example of such a redesigned keyboard is disclosed in U.S. Pat. No. 4,597,681 in which the keyboard is divided laterally into two halves supported on rectangular base plates which are connected by a transverse hinge so that they may be elevated at an angle relative to each other in an inverted V configuration. In addition, each of the keyboard halves is pivoted at one corner thereof, so that it may be rotated relative to the supporting base plate, thus allowing the orientation of the halves to be adjusted relative to each other. However, the extent to which such adjustment can be accommodated is significantly limited by the mechanical configuration of the support mechanism.
Another bifurcated keyboard arrangement is disclosed in U.S. Pat. No. 4,661,005, in which the respective keyboard halves are slidable transversely outward relative to each other along a track affixed to the edge of a table which supports a video screen. In addition, each keyboard half is hinged along a horizontal axis parallel to the track so that it may be rotated downward (and thus inclined toward the operator) and is pivoted so that it may also rotate about a second horizontal axis perpendicular to the track. In this manner the relative orientation of the two keyboard halves is once again adjustable within a range which, however, is limited by the mechanical constraints of the hinges and tracks, etc. In addition, the supporting apparatus requires specially fabricated hardware which makes it relatively expensive and not easily portable or interchangeable with a conventional commercial keyboard.
Other efforts to develop an adjustable keyboard arrangement, such as U.S. Pat. No. 4,509,873, suffer from similar disadvantages.
One object of the present invention, therefore is to provide a bifurcated keyboard arrangement in which the separated sections are easily adjustable in a virtually limitless range of orientations to conform to the comfort requirements of an operator.
Another objective of the present invention is to provide a bifurcated keyboard arrangement which is simple and inexpensive to manufacture.
Yet another objective of the present invention is to provide a bifurcated keyboard arrangement which is compact, convenient and easily portable.
Still another object of the invention is to provide a bifurcated keyboard arrangement in which the keyboard sections are freely rotatable about three mutually perpendicular axes, thus providing, among other things, the ability to rotate each keyboard section away from the operator in order to achieve any desired position necessary to provide ergononmetric relief to the operator.
Finally, another objective of the present invention is to provide a bifurcated keyboard arrangement which may be quickly and easily connected to a computer or other information processing device and used as a replacement for a conventional commercial keyboard, without the need for elaborate specially fabricated hinges, tracks or other special purpose hardware.
These and other objects and advantages are achieved according to the invention in which a conventional keyboard is divided into two sections, each of which is supported on a joint, which is freely rotatable and pivotable, such as a conventional ball and socket joint or a joint of a type commonly used to support, computer monitors. The joint in turn may have a support adapted to rest on a table top or other support surface, or it may be mounted on a suction cup adapted to adhere to such a supporting surface. In another embodiment, the pivotable joint has a supporting clamp which can be affixed to the edge of a supporting table. In a further embodiment, the pivotable joint is supported on arms which are themselves pivotably mounted to a table in a conventional manner, or may be clamped to a table edge. In yet another preferred embodiment, the joints supporting the respective keyboard sections are mounted on a base assembly, which may have an adjustable width so that the separation between the two keyboard sections can be varied.